----- Original Message -----
>
> Our QA group recently ran into a makedumpfile problem while
> testing kdump/makedumpfile w/upstream 3.7.1 kernels, which
> had to do with the filtering of pages on a 12GB ppc64 system.
>
... [ cut ] ...
>
> I haven't checked why the original math fails in the case of the
> ppc64 kernel, while it does not fail in a CONFIG_SPARSEMEM_EXTREME
> x86_64 kernel, for example. (page size maybe?) But obviously the
> simpler dimemsion-check is a better way to do it.
>
> Of course, within the current constraints of makedumpfile, it's not
> that easy. Ideally the kernel could pass the configuration in
> the vmcoreinfo with a VMCOREINFO_CONFIG(name). But anyway, I'll leave
> that up to you.
>
> Thanks,
> Dave
It's presumably being seen in 3.7.1 because of this commit:
$ git log -p arch/powerpc/include/asm/sparsemem.h
commit 048ee0993ec8360abb0b51bdf8f8721e9ed62ec4
Author: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Date: Mon Sep 10 02:52:55 2012 +0000
powerpc/mm: Add 64TB support
Increase max addressable range to 64TB. This is not tested on
real hardware yet.
Reviewed-by: Paul Mackerras <paulus at samba.org>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/sparsemem.h b/arch/powerpc/include/asm/sparsemem.h
index 0c5fa31..f6fc0ee 100644
--- a/arch/powerpc/include/asm/sparsemem.h
+++ b/arch/powerpc/include/asm/sparsemem.h
@@ -10,8 +10,8 @@
*/
#define SECTION_SIZE_BITS 24
-#define MAX_PHYSADDR_BITS 44
-#define MAX_PHYSMEM_BITS 44
+#define MAX_PHYSADDR_BITS 46
+#define MAX_PHYSMEM_BITS 46
#endif /* CONFIG_SPARSEMEM */
$ git describe --contains 048ee0993ec8360abb0b51bdf8f8721e9ed62ec4
v3.7-rc1~108^2~32
$
Dave
